Bulkhead for high-speed motorboats



. 16, 1941. H. scof|T-PA|NE Erm.

v BULKHEAD FOR HIGH-SPEED HOTORBOATS Filed April 13, 1940 Patented Dec.16, 1941 BULKHEAD FOR HIGH-SPEE MOTORBOATS Hubert Scott-Paine and GeorgeSidney Selman, Hythe, Southampton, England; said Selman assigner to saidScott-Paine Application April 13, 1940, Serial No.y 329,563 In GreatBritain March 9, 1939 2 Claims.

This application corresponds to the application of Hubert Scott-Paineand George Sidney lSelman, Serial No. 7703/39, which was lle'd inGreatBritain on March 9, 1939.

In building high-speed motorboats, lit is desirable that the weight ofthe structure should be kept at a minimum, subject to adequate strengthbeing obtained, and the object of this invention is to provide a novelconstruction of bulkhead in such vessels.

It is, of course, usual to arrange a transverse bulkhead in way of atransverse frame, and if necessary to provide a special transverse frameat ythe desired location of a bulkhea-d.

According to this invention, a bulkhead for high-speed motorboats andlike vessels comprises the combination with a transverse frame, ofpillars and bracing-members secured to the frame, and a ply-woodcovering secured on the frame, pillars and bracing-members.

In a preferred form of construction, a solid timber lling occupies thelower part of the space enclosed by the transverse frame, the upper partof which space is occupied by said pillars and bracing-members.

The solid timber lling for the lower part of the bulkhead preferablyextends upwards to about the water-line of the vessel and above the topof the usual main longitudinal framing of the bottom of the vessel.

Preferably the bracing-members comprise cross-members which are securedto the vertical pillars, and it is further preferred that these shouldbe aligned where possible respectively with certain longitudinalframe-members or stringers of the vessel.

According to yet another feature of the invention, brackets used forreinforcing the joints between the members of the transverse frame aresecured outside the ply-wood covering.

The following is a description of one form of the invention, referencebeing made to the accompanying drawing, in which,

Figure l is a section through a part of the boat athwartships showing abulkh-ead in side elevation, certain parts of the bulkhead being cutaway to expose its internal construction,

Figure 2 is a section on the line 2-2 of Figure 1, and

Figure 3 is a horizontal section through the joint between alongitudinal frame-member and a bulkhead on the line 3-3 of Figure 1.

Each bulkhead is built into one of the transverse frames of the boatwhich frame is built and all of the same thickness in the case of aboat, say, 60 or '70 feet long, in which the beam measures about 16 feetand the height from the keel 'I I to deck about '7 feet, and theframe-members aforesaid are 1% `inches thick. The lower part of thespace enclosed by this frame, up to 'a heightgo'f about ,3 feet from thekeel, which is approximately the draught of the vessel at thisparticular section, is occupied by a solid white mahogany (larana) plankI3 also 1% inches thick, shaped on vits sides I4 and lower edge I5 t0 bebedded on the frame-members, with its upper edge 'I5 horizontal. Abovethis block there are provided vertical pillars I8 extending from it upto the deck beam of the transverse frame and these pillars are halved-inand screwed at I9 at the top and bottom to provide a rigid structure.These pillars are spaced about a foot apart but the spacing is adjustedso that the pillars will align with the longitudinal members such as I'lWhere possible.

The transverse frame is provided with crossmembers 20 which are alsospaced about a foot apart, but the spacing again is adjusted to alignthem with the side stringers 2l where possible and the cross-members arehalved-in and screwed at 22 to the vertical pillars.

There is thereby provided a structural framing for the bulkhead whichprovides a Very substantial transverse reinforcement to the strength ofthe boat.

This transverse framework is then covered on the two sides by ply-woodsheets 23 and 28, respectively, the sheets overlapping the framemembers,pillars and cross-members I0, I8 and 20 respectively, and preferablyhaving their edges finishing flush with the inner surface of the bottom,side and deck stringers 24, 2| and 25 respectively. All the verticalpillars and crossmembers are made of the same thickness as theframe-members I0, namely 11A inches in this particular example, so thatthe ply-wood lies flush on the whole structure and is screwed or other-Wise fixed thereto where necessary. Brackets 2E are secured outside theply-wood sheet over the joints between the frame-members Ill. Thelongitudinal frame-members I1 at the bottom of the boat are formed in anumber of parts which are arranged at each bulkhead to abut against theply-wood coverings 23 and 28 opposite the plank I3 and are held rmly inline by means of angle plates 32 which are bolted together on eitherside of the bulkhead by bolts 33.

The use of a solid iilling for the lower part of of timbers or membersof appropriate thickness, the bulkhead prevents any accumulation ofwater or moisture inside that part of the bulkhead, and drainage andventilation apertures may be provided where necessary in the other partsof the bulkhead so that access tQ the enclosed space is afforded fromone side of the bulkhead only. Preferably the ventilation of the spacein the transverse frame between the ply-wood coverings is eiected by theprovision of shallow grooves 21 formed in the faces of the pillars andcross-members on one side thereof which grooves communicate on the onehand with small holes 3| in the upper part of one of the plywoodcoverings and on the other hand with cross grooves 30 formed in thecross-members.

It will be seen that this invention provides a transverse bulkhead whichis of great strength for its weight as compared with known constructionsof bulkhead, and moreover it provides a satisfactorily watertightbulkhead. If it is desired to provide communication through it, anysuitable construction of watertight door can be employed.

We claim:

1. A bulkhead for high-speed motor-boats and like vessels comprising, incombination, a transverse frame extending around the inside of the hullof the boat and including a deck beam, the lower part of the spacedefined by said frame being lled by a plank the upper edge of whichextends to about the water-line of the boat, a plurality of spacedvertical pillars extending from the upper edge of said plank to the deckbeam and secured thereto, a plurality of spaced horizontal cross-membersextending between the intermediate pillars and between the outermostpillars and the frame and secured thereto, the said frame, plank,pillars and cross-members all being of the same thickness and having ushsurfaces, and ply-wood panels completely covering both sides of saidframe, plank, pillars and cross-members.

2. A bulkhead for high-speed motor-boats and like vessels comprising, incombination, a transverse frame extending around the inside of the hullof the boat and including a deck beam, the lower part of the `spacedefined by said frame being lled by a plank the upper edge of whichextends to about the Water-line of the boat, a plurality of spacedvertical pillars extending from the upper edge of said plank to the deckbeam and secured thereto, a plurality of spaced hori- Zontalcross-members extending between the intermediate pillars and between theoutermost pillars and the frame :and secured thereto, the said frame,plank, pillars and cross-members all being of the same thickness andhaving flush surfaces, ply-wood panels completely covering both sides ofsaid frame, plank, pillars and cross-members, and Ventilating meansproviding communication with the spaces dened by said frame, pillars,cross-members and panels said Ventilating means comprising grooves cutin the surfaces of said pillars and cross-members which lie against saidpanels, said grooves being in communication with said spaces and withthe outside of the bulkhead through openings in its upper portion.

HUBERT SCOTT-PAINE. GEORGE SIDNEY SELMAN.

